package com.base.duotai;

class A1 {
	public void tell1() {
		System.out.println("B -- tell1");
	}
}

class B1 extends A1 {
	public void tell2() {
		System.out.println("B -- tell2");
	}
}

class C1 extends A1 {
	public void tell3() {
		System.out.println("C--tell3");
	}
}

class D1 extends A1 {
	
}

public class DuotaiDemo02 {

//	public static void main(String[] args) {
//		 say(new B1());
//		 say(new C1());
//		 say(new D1());
//	}
//	
//	public static void say(A1 a){
//		a.tell1();
//	}
	
	public static void main(String[] args) {
		A a=new A();
		System.out.println(a instanceof A);
		System.out.println(a instanceof B);
	}
	
}